Explosive ordnance construction



Jan.'l9, 1960 R. D. HUNTOON 2,921,518

EXPLOSIVE ORDNANCE CONSTRUCTION F iled May a, 1944 FIG. 3

INVENTOR RUBERT D. HUNTOON ATTORNEY 2,921,518 Patented Jan. in, 1960 EXPLOSIVE ORDNAN CE CONSTRUCTION Robert D. Huntoon, Silver Spring, Md., assignor to the United States of America as represented by the Secretary of the Navy Application May 6, 1944, Serial No. 534,517

10 Claims. (Cl. 102--2) (Granted under Title 35, US. Code (1952), sec. 266) This invention relates to electrical excitation of items of explosive ordnance and more particularly to the functioning of certain parts thereof as an antenna.

A primary object of the invention is to provide means adapted to excite portions of a bomb or other projectile in a novel manner causing the casing and fin surfaces thereof to act as an antenna, or to act as a portion of an antenna system, by creating electrical fields.

Another object is to provide means, housed within the fin structure, or in an adjacent attachment to the bomb, for passing a high frequency electrical current through the fin structure, which in turn sets up an electrical field between the fin surfaces and the bomb casing, whereby the entire assembly may act as a radiating system.

Another object is to provide a fin support for a bomb which when traversed by a high frequency electrical current will cause the fin surfaces and bomb casing to maintain an electrical field, whereby the entire assembly may act as a radiating system.

In the drawings:

Fig. 1 is a side elevation, partly in section and partly broken away, of a bomb provided with fin structure and associated electrical components constructed in accordance with the present invention.

Fig. 2 is a rear elevation thereof.

Fig. 3 is a diagram of a circuit which is electrically equivalent to that employed in the device of Figs. 1 and 2.

As shown in Figs. 1 and 2, an open-ended, box-like fin structure 1 is attached to the rear end of bomb 3 by means of radial fins 2 which are welded to the corners of the box fin structure 1. Portions 11, which form continuations of fins 2, extend angularly inwardly and are welded to bomb body 3, as indicated. Coaxial metal cylinder 4, having a closed front end and open rear end, is welded to the inner ends of corradiating struts 5, in a position longitudinally spaced from the rear end of the bomb. The outer ends of struts 5 are welded to the inner surfaces of box fin elements 1 substantially at their mid-points. Metal cylinder 6, closed at its rear end, occupies a coaxial position between the bomb and cylinder 4, being welded to the bomb at its forward extremity and provided with a single central opening (undesignated) in its rear face.

Cylinder 6 is of larger diameter than cylinder 4 and is of such length that a relatively thick disc 7 of Bakelite or other insulating material may be fastened between the adjacent faces of cylinders 4 and 6, as by means of cement and/or countersunk rivets 16. Disc 7 has a central bore which is aligned with the central opening in the face of cylinder 6, and a conductor, connected at 8a to the centerof the adjacent face of cylinder 4 and insulated from cylinder 6, is passed through these openings and connected to one end of inductance 8 which is shunted by tuning condenser 9. The other terminal of inductance 8 is connected at 8b to the wall of cylinder 6. Thus it is evident that insulating disc 7 forms a gap in the inducting circuit, and across this gap high frequency current is applied to set up the circulating currents. I

Inductance 8 constitutes the secondary of an antenna transformer, the primary 10 of which is connected to the output terminals of a suitable oscillator 17, also housed in cylinder 6. Oscillatory currents induced in coil 8 will in turn cause oscillatory currents to flow in the circuit comprising cylinder 4, struts 5, fins 1, fins 2, fin support 11, bomb casing 3, cylinder 6, and so back to cylinder 4, through the capacitance existing between the cylinder faces. Disc 7 serves both as a structural member and as a dielectric for the condenser formed by the cylinder faces.

Broken line 20 indicates one loop of the circuit. The impedance drop across inclined portions 11 of fins 2 creates a potential difference between the principal fin structure and bomb casing 3, exciting the whole bomb casing or body 3, which acts as a radiating antenna, in conjunction with the fin structure. The antenna system, considered as a whole, may of course, also be used for receiving radiation. In either case tuning may be accomplished by means of variable condenser 9.

In Fig. 3, representing the equivalent circuit, the points 12-42 are the equivalent of the points of application of antenna load across coil 8. Resistance 13 represents the radiation resistance and ohmic losses of the circuit, condenser 14 the circuit capacitance, and coil 15 represents the circuit inductance.

While I have shown and described a preferred method of exciting bombs to act as radiators or receivers of electrical energy in accordance with my invention, many changes of detail may obviously be made without departure from the general principles thereof.

The invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

I claim:

1. An explosive missile having a metallic body portion, a terminal fin structure of tubular form projecting coaxially from the body and electrically connected thereto, metallic supporting fins converging from the fin structure to the body and cooperating therewith to form portions of a radiating loop circuit, a pair of tubular terminally abutting, connecting and radiating elements also projecting coaxially from the body portion and into the space bounded by the fin structure, said elements being insulated from one another and one thereof being connected to the fin structure and the other to the body, and means for electrically exciting the loop circuit, including an oscillator housed at least partly in one of said tubular elements.

2. Means as set forth in claim 1 in which said housed oscillator portion is contained in the tubular element nearer the body portion, said other tubular element being open at its end farther from the body portion.

3. Means as set forth in claim 1 including strut means connecting one of said tubular elements to the fin structure at a point remote from the body portion.

4. Means as set forth in claim 1 including strut means connecting one of said tubular elements to the tin structure at a point remote from the body portion, the other tubular element being interposed between the body portion and the tubular element first mentioned, said housed oscillator portion being contained within one of said tubular elements and electrically connected to both thereof.

5. Means as set forth in claim 1 including means connecting one of said tubular elements to the fin structure at a point remote from the body portion, the other tubu- 7 3 lar element being interposed between the body portion and the tubular element first mentioned, said housed oscillator portion being contained within said second mentioned tubular element and electrically connected to both of 'said elements. 7

6. An explosive missile having a metallic body portion, a terminal fin structure of tubular form projecting coaxially from'the body and electrically connected thereto, metallic supporting fins converging from the fin structure to the body and cooperating therewith to form portions of a radiating loop circuit, and a pair off-tubular terminally abutting, connecting and, radiating elements also projecting coaxially from the body portion and into the space bounded by the fin structure, said elements'being insulated from one another and one thereof being connected to the fin structure and the other to the body.

7. Means as set forth in claim 6 including strut means connecting one of said tubular elements to the fin struc-,

ture at a point remote from the body portion. 7

' 8. Means as set forth in claim 6 including strut means connecting one of said tubular elements to the fin structure at a point remote from the body portion, the other tubular element being interposed between the body portion and the tubular element firstmentioned.

9. In an explosive missile having a metallic body portion, a metallic fin structure spaced from said body portion and including radially extending interconnected stabilizing fins, metallic connecting members of relatively small cross section rigidly joining said fin structure to said body portion, means forming a condenser having one plate connected to said fin structure and the other plate connected to said body portion to form with said fin structure, connecting members, and body portion a radiator loop circuit.

10. Means as set forth in claim 9 including means for generating high frequency oscillating currents in said loop circuit.

References Cited in the file of this patent UNITED STATES PATENTS France Apr. 24, 1939 

